Grease manufacture



May 11, 1943. A. E. CALKINS 3 5 GREASE MANUFACTURE Filed June 24, 1940PEEIIEATEZ G A ra? ALTER CONTRO Z/AL VE Patented May 11, 1943 2,318,668GREASE MANUFACTURE Austin E. Calkins, Westfield, N. 1., assignor toStandard Oil Development Company, a corporation of Delaware ApplicationJune 24, 1940, Serial No. 342,081

. 14 Claims. (Cl. 252-39) This invention relates to a new process formanufacturing lubricating greases, and to the products obtained thereby,as well as the particular type of equipment used in making thesegreases. The invention relates more particularly to a continuous processfor blending a preformed soap stock in various proportions with minerallubricating oils of the desired viscosity, in order to produce varioustypes and grades of lubricating greases.

There have been several attempts in the past to develop continuousprocesses for manufacturing lubricating greases but for various reasonsthesehave not met with the desired success. For instance; it has beensuggested to feed a finely divided soap in solid form and a mineral oilinto a high-speed centrifugal pin disc mill, but satisfactory dispersionis not obtained because that procedure is,not even recommended for limesoap greases containing 15% or less of soap in the finished grease, andeven the greases containing the recommended range of 16% to 24% of limesoap must be kept boiling for 15 to 30 minutes or longer after it hasbeen discharged from the mill. Another proposal was to continuously feeda solution of fatty oil in hydrocarbon oil through a series of tubes ina furnace heated with a suitable burner, and then continuously injectalkali into that heated oil mixture at various points during itsprogress through the furnace. This procedure has several disadvantagesincluding that when the fatty oil or fatty acid-is diluted withall ofthe mineral oil to be used in making the grease, slow and poorsaponification is obtained, unless excessively high temperatures areused and that very poor mixing is obtained in the tubes with resultantdanger of burning and uneven saponification. Other suggestio'ns involvethe actual preparation of a grease and then subjecting the latter'tosome treatment such as in a colloid mill, in order to homogenize it, andto remove any lumps of unpast is that the art of making good grease isfraught with many difiiculties and uncertainties. Apparently, in orderto obtain a satisfactory grease structure, (which in itself is somewhatdifficult to define), a number of very sensitive factors must becontrolled precisely; in fact, it seems to be well recognized that yearsof actual experience are necessary in order to make highquality greasesand that this art cannot be learned simply from studying instructionsfrom a book. That is primarily why, commercially, practically all highquality greases are made by the batch process.

The primary object of v the present invention is to develop a continuousprocess for making finished greases, by which advantage can be taken ofthe experience acquired by the grease operator in making a satisfactorysoap stock for ment of many large blending'tanks or kettles.

Another object is to develop a grease-making process which requiressubstantially lower equipment installation cost than processes usedheretofore, and at the same time to develop a process which willmanufacture high quality lubricating evenly dispersed soap. Apparentlythe only field greases but is not suitable for higher quality products,chiefly because a substantial excess of lime must be used in order toget a reasonably quick saponification; also, greases made by thisprocedure, have a large breakdown in consistency upon working.

The chief reason for this lack of success in the greases moreeconomically than could be done in the past. These and other objects andadvantages, of the invention will appear more clearly from the followingspecification.

Broadly, the invention comprises a continuous process of grease makingby continuously, and preferably automatically, mixing togetherproportioned amounts of heated preformed soap stock, preferably in theliquid state, and a heated mineral oil. i v

The soap stock may be prepared by any known method. For instance, thedesired fat or fatty acid may be dissolved; in the mineral oil, heatedto the desired temperature and then saponified by adding the desiredmetal hydroxide or other suitable derivative. may be used.)

Another procedure is to mix lime and fat (with a small amount of waterif desired) and heat the mixture until saponification has beencompleted, at which time a small amount ofmineral oil may be added ifdesired in order to make the soap stock more fluid at the temperature atwhich it is desired to be blended in later for making a finished grease.

A third alternative is to make one mixture of a portion of mineral oilwith the fatty acid or fat to be used, and make another mixture com- (Insome cases the oxide prising a suspension of the hydrated lime orcaustic soda in another portion of mineral oil and then mix these twomixtures together, maintaining the desired temperature untilsaponification has been completed.

A still different procedure, and one. which is preferred for thepurposes of the present invention, is to mix the fat or fatty acidtogether with the lime or other saponifying agent, a small amount ofmineral oil and water (if any is to be used), all together in asteam-jacketed pressure kettle, bolt on the lid and then heat to 250'to325 F., or sufficiently to effect complete saponification, maintaining aslight superatmospheric pressure such as about 35 to 75 lbs. gauge.Pressure is used during the manufacture of the soap stock to acceleratesaponification because it is desired to maintain the grease underpressure throughout the subsequent blending with mineral oil, until thegrease is ready to be discharged into shipping packages.

, In making a lime soap stock by the preferred procedure, the mixtureofraw materials is heated to about 300 F., and cooked for 1 or 2 hoursuntil saponification is completed; this is judged by examining a smallsample of the product from time to time and examining its consistency oranalyzing it.

In preparing the soap stock, any desired saponiflcable material can beused, but it is preferred to use those containing fatty acid radicals ofat least carbon atoms. Either natural or synthetic materials can be usedand either single materials or mixtures blended in order to obtainmodified properties in the soap stock can be used. Suitable oils, fats,and fatty acids include those of animal, vegetable and fish origin,although the animal type are preferred. These fatty materials may beeither saturated or slightly unsaturated but preferably not of thedrying oil type. Besides the most common lard and tallow, examples ofsuitable materials include "beef tallow, bone fat, castor oil, corn oil,cottonseed oil, cottonseed stearin, horse fat, lard oil, animal or hogfat, and wool fat or mixtures thereof. Examples, of suitable fatty acidsinclude preferably those having 15 to 20 carbon atoms, oleic acid,stearic acid, animal fatty acids, cottonseed fatty acids, petroleumnaphthenic acids and vari ous synthetic fatty acids such as thoseobtained by oxidation of paraflln-wax. Mixtures of fats and fatty acidsmay be used. Whether a fat or a fatty acid should be used, dependsprimarily upon whether glycerine is desired in the resulting soap stockbecause the saponification of a fat produces glycerine as a by-product.Also'it is preferred to saponify the fat or fatty acids in the absenceof mineral oil and then blend with mineral oil to a so-called soapstock. A

Although the invention was primarily developed, and appeared to haveoutstanding advantages, for manufacturing calcium soap greases, othermetal base greases may be used, for instance, sodium and aluminum,- ormixed metal soap greases, e. g. sodium-calcium, or sodiumaluminum, etc.Such mixed greases are preferably made from mixed metal soap stocks, 1.e. either two soaps are pre-mixed or they are made simultaneously byadding, for instance, both line and soda to the material to besaponiiled. Greases may also be prepared from soaps of other metals suchas potassium, lead, etc. although calcium, sodium, and aluminum are themost commonly used.

The composition of the soapstock to be used for blending according tothe present invention, will depend upon several factors, chief of whichis the type of metal used in making the soap. For instance, a calciumsoap stock should preferably contain about to or more soap, about 10%to'50% of oil, about 5% to 15% or even 50% or more of water, and 0% to8% or so of glycerine. The sodium soap stock should preferably containabout 30% to or soap, about 25% to 70% of oil, about 0% to 1% of water,and about 0% to 8% of glycerine. stock will preferebly contain about 15%to 50% of soap and about 50% to of oil, usually no water, and perhaps 0%to 5% of glycerine, if desired. In general, the soap stocks therefore,will contain about 10% to 50% of oil and although.

TABLE 1 Pt cent/weight Metal base Soap Oil Water Glycerin Total Calcium65 22 8 5 Sodium 50 45 1 l 4 100 Aluminum 25 72 0 3 100 If any solidfillers are to be used in the fin-' ished grease, where the content ofsolid fillers may be from 0% to 40% by weight, such fillers arepreferably incorporated into the soap stock during or after thepreparation thereof. Some of the fillers which can be used includegraphite, talc, asbestos, sulphur, etc.

Other materials, especially materials which have to be melted in orderto be properly mixed,

- should preferably, if to be used at all, be mixed into the soap stock,for instance, oxidized asphalt, e. g. of penetration, petrolatum, waxtailings, vegetable waxes, e. g. camauba wax, etc. Such materials may bedesirably used for preparing block greases, e. g. for open bearings orwhere the grease is applied as a lump.

Suflicient soap kettles of any conventional type equipped to meet therequirements of the process should be used to provide a constant supplyof 'soap stock by timing the charges to the kettles so that one kettleof stock is always on hand completely finished, before another isexhausted so that a continuous supply of soap stock may be fed to thegrease blending mixer.

The mineral oil to be used, referring either to the small amount whichmay be used in preparing the soap stock as stressed above, or the mainbulk of oil to be blended with that soap stock as will be discussedhereinafter, may be any type of mineral oil stock normally usedheretofore in batch operation for making the various types and grades ofgreases, for instance, mineral lubricating oili derived from varioustypes of crudes, such as parafiinic, naphthenic, or mixed base crudes,may be used, as wellas distillates or residual fractions thereof, withor without various treatments, such as clay treating, acid treating,extraction with selective solvents, such as liquid sulfur dioxide,phenol, etc., or lubricate ing oil fractions obtained by more or lesssyn- An aluminum soap thetic chemical processes, such as polymerization,condensation, hydrogenation, etc. Various natural or synthetic mixturesor blends may be used, for instance, one type of mineral oil may be usedin making the concentrated soap stock and one or more other oils may beused in makgrease the 011 should have a viscosity of about 35-300seconds at 210 F'. but preferably 40-200 seconds at 210 F., and for analuminum soap grease the oil should preferably have a viscosity of about45-300 seconds Saybolt at 210 F. and preferably about 50-200 seconds at210 F.

If any oil-soluble addition agents are to be incorporated in thefinished greases, they should preferably be added to the oil stock.Various addition agents which may be added include, for instance,oil-soluble dyes (about 0.01% to 1% by weight on the finished grease),stringiness addition agents to about 2% by weight), polyisobutylene, e.g. MOO-200,000 molecular weight, preferably above 30,000 molecularweight, e. g. 70,000 to 80,000 molecular weight, or natural or syntheticrubber; anti-oxidants (0.01 to about 0.3%), e. g. phenyl alpha naphthylamine, glycols, phenols, phenolic ethers, amino phenols, alpha naphthol,etc.; and extreme pressure lubricating addition agents (0 to about 20%by weight) e. g. sulfurized fatty oils, chlorinated orsulfur-chlorinated hydrocarbons, etc., and various other materialscommonly used in lubricating greases.

The oil stock to be blended for making the various greases shouldpreferably be preheated, which can be accomplished readily by passingthe oil through suitable heater or furnace, or by any other suitablemethod, as the oil stock is also preferably delivered under slightsuperatmospheric pressure, such as about 20 to 50 pounds so that theentire grease blending system will be under substantially evensuperatmospheric pressure. Pipe lines from, supply tanks of variousgrades of mineral oil may be so selected and equipped with suitablevalves so that any one oil, or a mixture of any two or more, may be usedas desired.

The heated preformed soap stock and the heated mineral oil to be usedfor the blending are now ready to be mixed continuously according to thepresent invention. In order to explain this operation more easily,reference will be made to the accompanying drawing which is a schematiclayout of suitable equipment for carrying out the invention.

Referring to the drawing, it is seen that the desired oil stock Iobtained from one or more suitable sources such as A, B, C and D, ismixed with a soap stock prepared in soap kettle 2, by passing themthrough the mixer 3 after having been proportioned or metered out by thegear pump for the soap stock and gear pump 5 for the oil stock. The feedof the pumps 4 and 5 may be controlled by hand if desired or preferablycontrolled by the automatic proportioner 6 which can be addusted to givea wide range of proportions of the soap stock and the oil stock and atthe same time it is-so designedsh t ith any particular proportion ofsoap and oil, the total capacity or throughput of both may be increasedwithout disturbing the proportions of each. The mixer 3 may be any oneof a number of high speed mixers in which the materials to be mixed arebrought into contact in a highly turbulent zone, whereby efilcientdispersion is obtained by means of the shearing action of rapidly movingparts alone or combined with the directioning effect of one or moresmall vanes or baflles. The preferred type of mixer is a centrifugalpump or a mixer known in the industry as the Lancaster disperser. Thislatter machine consists essentially of a horizontal operating tube withduplex dispersing mechanism each consisting of two impellers attached tothe shaft with a set of stator vanes held by tubed wall betweenimpellers. The impellers of one mechanism are of opposite hand to thoseof the other set, so that the thrust of the two sets of impellers istherefore counterbalanced, practically eliminating end thrust load onthe bearings. The radial length of the impeller blades is relativelysmall so that all the material processed is confined to a thin annularring where it is subjected to a high average peripheral velocity. I

Also other types of mixers include a centrifugal pump, or a plurality ofsuch pumps arranged in series so as to obtain more mixing and a finedegree of dispersion, or other types such as a screw pump or screwconveyer, high speed mills, such as a colloid mill, roller or disc millor paint mills, etc. I

The grease issuing from the mixer 3 may then be passed through suitablefilter l and if desired a cooler 8 and then, after going through aloaded pressure controller 9, is discharged or filled into grease cansfor storage or shipment. As indicated in the drawing, by suitable pipelines and valves the grease may be bypassed aroundthe filter and cooler.

.An example of the grease making operation is as follows: I Oil stock Imay be heated to the desired temperature in a suitable preheater l0; andthe soap kettle may .be heated by any suitable means, such as by steamjacket I l or by direct fire. The soap kettle 2 is also provided withsuitable agitators i2 which may be driven byany suitable source of powernot shown. The materials to be used in making the soap stock may becharged into the soap kettle in any desired manner. One way of doingthis is to admit the water near the bottom of the kettle througha line'13, admit the small amount of mineral oil near the top of the kettlethrough the line I l and charge the saponifiable material and metalcompound, e. g. hydrated line, caustic soda, etc., or a preformed soap,e. g. alu-' minum stearate or aluminum naphthenate, etc., through thecharging openings I5. It is to be understood of course that the entiresystem will" be provided with suitable pressure gauges, safety valves,thermometers and control valves, as

needed for proper operation of the equipment according to the purview ofthe invention. If desired, the steam jacket around the soap kettle maybe connected to water lines so that if the soap stock has been prepared,it may be cooled by passing water through the catalyst jacket.

The length of time during which the soap stock and oil stock aresubjected to mixing will of course depend upon the type mixer used butwill normally vary within the approximate limits of 5-30 seconds, andpreferably from about 10-20 seconds.

As suggested previously, it is Preferred to have the entire systemincluding the oil feed lines, the

soap kettles, the proportioning pumps, and the mixers, including alsothe filter and cooler if such are used, under a slight superatmosphericpressure of, for instance, from about 15 to 50 lbs/sq. in. The primaryreason for this is to prevent the evaporation of water when makingcalcium soap greases, because anhydrous calcium soap usually will notmake a grease having a suitable grease structure. The water contentshould be about 525% (on the weight of dry soap present). Ten

' per cent would be theoretically correct but in practice a slightexcess is desirable so that at least about 12% is the preferred amount.The use of superatmospheric pressure also assists in preventing foaming.The exact pressure to be used, as will be obvious to those skilled inthe art, will depend upon the temperature to which the soap stock or thefinished grease is heated, the higher these materials are heated, thehigher the pressure will have to be in order to prevent evaporation ofthe water.

as aoca parts by volume of the heated oil stock are mixed with 1 part byvolume of the heated preformed soap stock, although usually theproportions are somewhat narrower, namely. about 3 to 15 parts by volumeof oil to 1 part by volume of soap stock. The blending or mixing may beaccomplished either in one stage or in a plurality of stages as desired,for instance, if it is intended'to make a grease with a very low soapcontent, such as a calcium soap content of about 5% in the finishedgrease. one might start with a soap stock containing 65% of calciumsoap. and first mix 1 volume of that soap stock with 4 volumes of oiland then re-mix 1 volume of the resulting grease with about 3 volumes ofoil. By this use of a plurality of stages for the mixing, a betterconversion is obtained than can be done in a single stage when beapproximately 125-450" F. in order to obtain about 2'15-350 F. The soaptemperature should be about 190-450 F. or even as low as 125 F. if thesoap stock already contains a substantial amount of oil, or preferablyabout 190-300 F. for lime soaps, about 300-350 F. for aluminum soaps,andabout 250-450" F. for soda greases. Lower temperatures tend topreclude proper solubility and dispersion, while excessive temperaturestend to cause burning and undesirable decomposition of some of theorganic constituents in the soap stocks. The resultant greasetemperature should be within the approximate limits of ISO-450 F. andpreferably about 175-210 F. for lime greases, about 250-350 F. foraluminum greases, and about 150-450 F. for soda greases. Especially whenmaking a lime soap grease, temperatures below 175 F. tend to cause adecrease in the yield, by which term is meant the relation between theA. S. T. M. penetration of the grease for any particular soap content.The temperature of the oil stock and the soap stock must, be balanced inorder to obtain the abovementioned desired range of temperature in thefinished grease.

The proportions in which the soap stock and the oil stock are to beblended in order to make the finished grease, depend of course upon thetype and grade of grease desired and upon the type of metal soaps used,i. e. whether calcium, sodium or aluminum soap is used, the viscosityand other characteristics of the oil stock, and. whether other materialsare present, such as glycerine or finely-divided solid fillers. Usually,however, the amount of soap in the finished grease will be within theapproximate limits of 1 to 55 (1% soap giving a fluid grease), butpreferably between the limits of about 5-25%. As will appear moreclearly from the later discussion of the experimental data, the presentinvention has special advantages for greases containing less than about15% of soap, and this is particularly true of lime soap greases. Inorder to obtain the greases having the desired soap content, about 1 to20 starting with a very concentrated soap stock and ending with a verydilute or low soap content grease.

.When making aluminum soap greases, the

practice followed heretofore may be used if desired, namely, pouring'thefreshly made aluminum soap into pans, e. g. 3 ft. x 4 ft. x 6 in., topermit formation of the desired structure, and then put back into thekettle and re-stirred.

The present invention has many advantages, some of which were notedpreviously. One advantage is that it enables the use of more compactequipment for the commercial manufacture of greases; for instance, it isestimated that 2 small kettles of 50 gallon capacity each, when usedaccording to the present invention, are equivalent in capacity to alarge 600 gallon kettle when used according to the standard batchmethods used heretofore. Another advantage is that this inventionresults in a greater uniformity of product in commercial operation thanhas been possible heretofore. This uniformity evidences itself in thesoap content, consistency, color and stability of the greases.Furthermore, by reason of the uniformity in soap content, consistency,etc., this invention permits the manufacture of greases, especially limesoap greases, with a lower soap content than were heretofore consideredpossible tent, the following table is given showing the yield which canbe reasonably expected for manufacturing lime soap greases according tothe present invention. The "yield figures are expressed as the maximumworked penetration for various soap contents.

Tenn 2 Per cent soap The above figures do not mean, of course, that limesoap greases having a higher worked penetration cannot be made accordingto the present invention, if it is so desired, but these figuresindicate that if the optimum water content is used,

as indicated previously, and the operating conditions are controlled forthe purpose of making greases having the lowest possible penetration forany particular soap content, the resultant greases will normally have aworked penetration below the figuresindicated in the above table. Forvthe sake of comparison, it might be noted that a test of samplesof limesoap grease made by of the large commercial "producers of such products,showed that the lime soap greases containing 14% of lime soap had aworked penetration between the limits. of about 260-350 and that limesoap greases having a content of 20% of soap had a worked penietrationof 185-265. Obviously, therefore, since the soap is one of the mostexpensive ingredients in the finished grease, the present invention is adistinctly valuable contribution to the art by showing how it ispossible to commercially manufacture a uniform grease having asubstantially lower worked penetration than has been possible heretoforefor any particular soap content.

' centages of soap can readily be determined by interpolation orextrapolation.

In addition to the advantages mentioned above,

nine of the soap stock was mixed with 3.5! volumes of the oiliinaccordance with the teachings of this invention, the stop stock and oilstock be-' ing fed continuously through the mixer for about V2 hour, 8samples being taken out at approximately 3 minute-intervals throughoutthe run. The following data were obtained:

Soap temperature average F 250 Oil temperature average F 205 Mixedgrease temperature average F 185 Unworked penet. (A.S.T.M.) 160 Workedpenetration (A.S.T.M.) 266 vWater content per cent 0.85 Soap contentdo.. 15.7

The product was a buttery cup grease, very satisfactory in mostrespects, but owing to the fact that an open kettle had been used forthe preparation of the soap stock, more water had been boiled out of thesoap than had been expected and consequently the soap stock and theresulting grease had a slightly lower water content than is desirablefor the best yield (penetration for a given soap content). In otherwords, if a somewhat larger amount of waterhad been used (about 12% onthe weight of the soap) the worked penetration would have been about 210or 215 instead of 266. The consistency of the product of this examplecorresponds to a No. 2 grease the grease products of this invention arealso Lard ..parts by weight 3,000 Hydrated lime do 432 Oil do 1,194Water n 375 About 100-150 more parts by weight of water were addedduring the saponification and cooked out.

The lime, water and fat were mixed at about 150 F. in an open topsteam-jacketed kettle. The mixture was heated to boiling (about 212 F.)and cooked for 1 or 2 hours until saponification was complete. Then theoil was stirred in and the cooking continued until the resulting soapstock was .completely homogeneous.

The lard used in this test had an iodine number of 53 and asaponiflcation number of 190 and the mineral oil was a parafliniclubricating oil stock having a viscosity of seconds Saybolt at 210 F.,110 seconds at 100 F., with a viscosity index of 80 and a pour point of+15 F.

The composition of the resulting soap stock was as follows:

Per cent Soap 65.9 Oil 24.8 Water 3.5 Glycerine 5.8

By means of laboratory equipment comprising 2 gear pumps controlled byan automatic proportioner for metering the desired proportion of soapand oil, and a centrifugal pump for mixing the proportioned amount ofsoap and oil, 1 vol- (according to the National Lubricating GreaseInstitute standards) and the throughput in this laboratory equipment wasabout 150 grams per minute or about 20 lbs. per hour. The pipe linesfeeding into the soap stock gear pump and the oil gear pump were A inchin diameter.

It is estimated that on a commercial scale in similar but largerequipment, two soap kettles each holding gallons or about 400 lbs. ofsoap stock would be used and pipe lines of about 2 inches in diameterwould be used, with a resulting throughput of about 15 lbs. per minuteor about 900 to 1000 lbs. per hour.

In order to show what a high degree of uniformity was obtained even inthis relatively crude experimental layout where of course the pipelines, gear pumps and mixer were subject to some change in temperatureeven though they had been insulated to some extent and were heated withelectrical resistance wires wrapped around them, the test results givingthe penetration and the percentage of water and soap in the 8 samplestaken throughout the run, are shown herebelow, together with a summaryshowing the maximum, minimum, and the difference for each property.

TABLE 3 #2 cup grease Penetration (A. s. 'r. M.) r"

Sample No.

332, Worked Water Soap The above table shows that in all of the 8samples tested throughout the /2 hour of continuous operation, thediflerence or spread between the maximum and minimum for the unworkedpenetration was only 12 points and for the worked penetration only 13points (from 261 to 274) the water content only 0.20% and the soap 0.7%(from 15.3 to 16.0). It is expected that with commercial operation, evenstill better uniformity can be obtained, but even these results areexceptionally good compared to successive batch operations according toprior art methods.

A large number of other continuous runs were made, using either limesoap or soda soap stock and using various proportions of soap to oil andvarious rates of throughput. The average temperatures oi the soap stock,the oil stock and the resulting grease, the throughput expressed inpounds per hour, the average soap content and worked penetration of theresulting grease, are

all tabulated in the iollowing Table 4; and the unworked and workedpenetrations, as well as the water content and the soap content of thevarious individual samples taken during the con? tinuous operation ofeach test, are shown in Table 5. The inspection of the several oils usedas the oil stock in the various tests is shown in Table 6.

The above data show that when various types and grades of greases areproduced according to the present invention, unexpectedly superiorresuits are obtained in regard to economy of operation, uniformity 01product, and production capaclty with relatively small compactequipment.

It is not intended that this invention be limited to any of theparticular examples which were given merely for the sake ofillustration, nor by any theory as to the mechanism of the operation ofthe invention but only by the app i ed claims in which it is intended toclaim all novelty inherent in the invention as broadly as the prior-Tuu: 4

Soap stock (parts by weight) Temperatures a e) Average Test'No.

r01. on Water Lime Hoop 011 Grease soap gg ge f Lime soap docks F. F. F.Lbalhr. Per cent 23.10 1.00 8.64 244 208 110 12 10.0 m 11.0 1.0 9.4 are200 a 10 11.8 187 no 0.0 9.0 204 212 110 10 10.1 214 11.00 8.0 9.00 no214 10a 13 9.1 281 11.00 0.0 9.30 208 220 192 18 9.0 an 11.00 0.0 0.00-209 201 110 10.0 m

e Soda 000 p stock: u Q

' 1 1: u m .30 oz.7'g i" 0 0 350 290 1.9 010 Turn 5 3. Process accordingto claim 1 in which the soap stock contains some oil. PenetrationComposition f 4. Continuous process of grease making which s em rcomprises continuously mixing together 1 volume 1;: Sample N0. of heatedpreformed soap stock containing 10% mg-ed worked soup to 86% by weightof oil and 15% to 75% by weight of soap, and 1-20 volumes oi heated min-Pa mm P" m eral oil in a high-speed mixerin which the soap 2 139 234 L901 stock and oil are brought into contact with each i? g 1-3? :g-g 55other in a highly turbulent zone, whereby em- 139 221 1 1 cientdispersion is obtained by means of the 1% 228 5g; shearing action ofrapidly moving parts, com- 3 94 "15;" 1 bined with the directioningeffect of a plurality g of small vanes, and thereby continuously pro- 971 00 ducing a finished grease containing 1% to a g-gg by weight of soap.5. Process according to claim 4, in'which the preheated soap stock ismaintained at a temper- TAB: 6 ature of 190 F. to 450 F., the preheatedoil is M h this oil was used maintained at F. to 450 F. and theresultant No of the tests m w c grease is produced at a temperature ofabout 7 6 sands, w F. to 450? F. 6. Process according to claim 1,carried out under superatmospheric pressure. 'mii """'i" 31 .1111:1315:1113: 3?:31132: 7o Process according to claim 1, carried out"EZIIIILII +20 o 50 ,3 3: crude Paraflinic. Naphthenic Paraflinlc.Napbthenic gggg pzg gfiz i' s ure of about 15- 1 1 ol 1 isobutylenehaving a molecular weight of about 16% p0 y in this oi 000 was dissolvedPennsylvania oil having a viscosity oi 165 seconds at 210 F.

8. Process according to claim 1 in which the mixing is effectedcontinuously in a highly turbulent zone by a high-speed mixer wherebyefll asracec cient and substantially uniform dispersion is obtained in atime not substantially exceeding 30 seconds.

9. Continuous process of grease making which comprises maintaining acontinuous supply of calcium soap stock, continuously mixing together ina high-speed mixer having a dispersing action substantially equivalentto that of the Lancaster disperser, 1 volume of said soap stock at atem-. perature of about 190 F. to 300- F., and 1 to 20 volumes ofmineral oil maintained at a temperature of 175 F. to 210 F., under asuperatmospheric pressure suflicient to prevent, vaporization of thewater in the soap stock under the temperature used, thereby continuouslyproducing a calcium soap grease at a temperature of about 175 F. to 210F.

10.- Process according to claim 9 in which the time of mixing is about5-30 seconds.

11. Process according to claim 9 in which the soap stock contains 10% to85% by Weight of oil and about to 75% by weight of calcium soap.

12. Continuous process of grease making which comprises continuouslymetering proportioned amounts of heatedpreformed soap stock in asemi-liquid state and a heated mineral oil by means of gear pumpsregulated by an automatic proportioner, and continuously mixing saidproportioned amount of soap stock and mineral oil together in aLancaster disperser.

13. Continuous process of making a lime soap grease which comprisesmaintaining a continuous supply of calcium soap stock having a tempera.-ture of about 190 F. to 300 F. and having subv stantially the followingcomposition by weight:

continuously mixing together in uniform controlled proportions onevolume of said soap stock with 1 to volumes of mineral oil maintained ata temperature of about 175- F. to 210 F., and

having a viscosity of about -100 seconds Sayboit at 210 R, in a highlyturbulent zone by a high speed mixer whereby eiiicient and substantiallyuniform dispersion of said soap stock and oil is obtained in a time notsubstantially exceeding 30 seconds, under a superatmospheric pressure ofabout 15-50 pounds per square inch sufficient to prevent vaporization ofthe water in the soap stock under the temperature used, therebycontinuously producing a calcium soap grease having a temperatureofabout F. to 210 F., and, without substantial further mixing, passing thefinished grease through a pressurereducing controller valve and drawingthe grease into containers for storage and shipping.

14. Process according to claim 1 in which the time of actual mixing isnot substantially more than 30 seconds. v

' AUSTIN E. CALKINS.

